Quantitative evidence-based thresholds for exfoliative cytology based early detection of dysplasia in oral potentially malignant disorders - a systematic review and meta-analysis.

[AIMS/OBJECTIVES] Cytomorphometry analysis in exfoliative cytology for the early identification of dysplasia in Oral Potentially Malignant Disorders (OPMDs) has gained interest. However, there are no standardized quantitative cytomorphometric reference values for dysplasia. Meta-analysis of cytomorphometry parameters to support a recommendation of quantitative values for discriminating between OPMDs as non-dysplastic or dysplastic lesions was carried out.

[METHODS] Using the PubMed, Scopus, and Web of Science, a search for relevant studies was undertaken using search phrases and keywords for identification. The mean values and standard deviations of cytomorphometric parameters for normal mucosa, OPMDs, and OSCC were extracted. A random-effects meta-analysis was performed and pooled values were obtained to establish a quantitative recommendation.

[RESULTS] Eight studies were included. Pooled estimates showed a decrease in cellular area (SMD: -1.50) and cellular diameter (SMD: -2.43), whereas an increase was observed in nuclear area (SMD: 2.35), nuclear diameter (SMD: 1.10), nuclear-cellular area ratio (SMD: 3.26), and nuclear-cellular diameter (SMD:1.74) in OPMDs with dysplasia compared to normal mucosa. A cellular area of less than 6058.33 square microns and a nuclear area greater than 139.40 square microns could indicate dysplastic changes. Similarly, a nuclear-cellular area ratio exceeding 0.058 may help differentiate normal mucosa from dysplastic OPMD.

[CONCLUSION] We recommend quantitative cytomorphometric values (CA < 6058.33 μm², NA > 139.40 μm², and NA:CA ratio > 0.058) as reference standards for identification of dysplastic changes in OPMDs. Cytopathologists and pathologists should use these recommended values when faced with a diagnostic dilemma regarding dysplasia in OPMDs.